The purpose of this Program-Project is the study of the mechanisms of cardiovascular disease so as to improve diagnosis, therapy and provide means for more accurate assessment and follow-up. There are three major areas of emphasis: 1) longitudinal study of the mechanisms and therapy of arrhythmias, 2) hemodynamic, metabolic, electrocardiographic and myocardial blood flow correlates of coronary artery disease and, 3) non-invasive techniques in the study of cardiovascular disease. It is the aim of the Program-Project to foster integration, application of information and innovation in the above areas through the interactions of personnel and provision of core facilities.